7C Populations in Ecosystems

Question 1

Ecosystem

Answer 1

All organisms living in a community and all of the abiotic conditions

Question 2

Biotic

Answer 2

All of the living features of an organism

Question 3

Abiotic

Answer 3

All of the non-living features of an organism

Question 4

Habitat

Answer 4

The place where an organism lives

Question 5

Niche

Answer 5

The role of a species within its habitat, for example what it eats and where it feeds
Biotic interactions- organisms it eats
Abiotic interactions- temperature range an organism can live in

Question 6

Adaptation

Answer 6

A feature that increases their chance of survival and reproduction

Question 7

Natural Selection

Answer 7

Better adaptations, more likely to survive and pass on the advantageous alleles

Question 8

Interspecific competition

Answer 8

Organisms of different species compete with each other for the same resources

Question 9

Intraspecific competition

Answer 9

Organisms of the same species compete with each other for the same resources

Question 10

Predation

Answer 10

An organism kills and eats another organism

Question 11

Methods for investigating populations

Answer 11

Quadrats, transects, mark release recapture

Question 12

What is the equation to do with mark-release-recapture

Answer 12

Total population size= (number caught in 1st sample x number caught in 2nd) / Number marked in second sample

Question 13

What are the assumptions that must be made in order for the mark- release- recapture method to be accurate?

Answer 13

The marked sample has had enough time to mix back into the population
The marking hasn’t affected the individuals chance of survival
There have been no changes in population size due to births, deaths and migration

Question 14

Dynamic ecosystem

Answer 14

The ecosystem is constantly changing

Question 15

Succession

Answer 15

The process by which an ecosystem changes over time

Question 16

Primary succession

Answer 16

Succession that takes place on land that has been newly formed or exposed

Question 17

Pioneer species

Answer 17

The first species to colonise an area. Must be adapted to grow under the harsh abiotic conditions The pioneer species then alter the abiotic conditions, making them less hostile so new organisms can start to live there

Question 18

Climax community

Answer 18

The largest and most complex community of plants and animals that an ecosystem can support

Question 19

Secondary succession

Answer 19

Takes place on land that has been cleared of all plants but where soil still remains- pioneer species are usually larger plants e.g shrubs

Question 20

Plagioclimax

Answer 20

Succession is stopped artificially by humans, preventing a climax community from developing, e.g mowing lawn

Question 21

Climactic Climax

Answer 21

The climax community for a particular climate

Question 22

Conservation

Answer 22

The protection and management of species and habitats in a sustainable way

Question 23

What are five methods of conservation?

Answer 23

Management of succession, seed banks, captive breeding, fishing quotas and protected areas

Question 24

How does managing succession aid in conservation?

Answer 24

Preventing succession preserves an ecosystem in its current stage of succession

Question 25

How do seed banks aid in conservation?

Answer 25

A store of seeds from lots of different plants. If plant becomes extinct, they can be reintroduced

Question 26

How does captive breeding aid in conservation?

Answer 26

Breeding animals in controlled environments, which increases their numbers, and prevents the species from becoming extinct